Darrell Blackwelder column: Azalea lace bug
My neighbor is concerned about her azaleas. They bloomed earlier and were beautiful, but now they look pale and sickly. She has problems with lace bugs. These are very small clear-winged insects that can be a problem on azalea and rhododendron during early summer. The leaves develop small, yellow splotches at the beginning stages of an infestation gradually progressing to pale yellow splotches. Premature leaf drop often occurs when plants are heavily infested.
Both immature and adult lace bugs are most often on the underside of leaves along with dark spots of excrement resembling dark varnish. Adult lace bugs have lace-like wings which appear to be clear and a lacy hood back of the head. The insects are very prolific and produce two or more generations in a year. Adults are about 1/8 inch long and 1/16 inch wide. This insect over-winters in the egg stage, hatching out in the spring to become a problem, usually just after bloom.
Repeated applications of insecticides are needed to effectively control lace bugs. Make the first application as soon as the young nymphs appear. Follow with a second application seven to 10 days later if needed. It is very important the underside of the leaves is completely covered for adequate control. Go to https://content.ces.ncsu.edu/azalea-lace-bug for detailed information on controlling azalea lace bug.
Darrell Blackwelder is the retired horticulture agent and director with the North Carolina Cooperative Extension Service in Rowan County. Contact him at firstname.lastname@example.org .